
<h1><span class="yiyi-st" id="yiyi-13">numpy.polymul</span></h1>
        <blockquote>
        <p>原文：<a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.polymul.html">https://docs.scipy.org/doc/numpy/reference/generated/numpy.polymul.html</a></p>
        <p>译者：<a href="https://github.com/wizardforcel">飞龙</a> <a href="http://usyiyi.cn/">UsyiyiCN</a></p>
        <p>校对：（虚位以待）</p>
        </blockquote>
    
<dl class="function">
<dt id="numpy.polymul"><span class="yiyi-st" id="yiyi-14"> <code class="descclassname">numpy.</code><code class="descname">polymul</code><span class="sig-paren">(</span><em>a1</em>, <em>a2</em><span class="sig-paren">)</span><a class="reference external" href="http://github.com/numpy/numpy/blob/v1.11.3/numpy/lib/polynomial.py#L791-L845"><span class="viewcode-link">[source]</span></a></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-15">找到两个多项式的乘积。</span></p>
<p><span class="yiyi-st" id="yiyi-16">查找从两个输入多项式相乘得到的多项式。</span><span class="yiyi-st" id="yiyi-17">每个输入必须是poly1d对象或多项式系数的1D序列，从最高到最低度。</span></p>
<table class="docutils field-list" frame="void" rules="none">
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<tr class="field-odd field"><th class="field-name"><span class="yiyi-st" id="yiyi-18">参数：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-19"><strong>a1，a2</strong>：array_like或poly1d对象</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-20">输入多项式。</span></p>
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<tr class="field-even field"><th class="field-name"><span class="yiyi-st" id="yiyi-21">返回：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-22"><strong>out</strong>：ndarray或poly1d对象</span></p>
<blockquote class="last">
<div><p><span class="yiyi-st" id="yiyi-23">由输入的乘法产生的多项式。</span><span class="yiyi-st" id="yiyi-24">如果任一输入是poly1d对象，则输出也是poly1d对象。</span><span class="yiyi-st" id="yiyi-25">否则，它是从最高到最低程度的多项式系数的1D数组。</span></p>
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<div class="admonition seealso">
<p class="first admonition-title"><span class="yiyi-st" id="yiyi-26">也可以看看</span></p>
<dl class="docutils">
<dt><span class="yiyi-st" id="yiyi-27"><a class="reference internal" href="numpy.poly1d.html#numpy.poly1d" title="numpy.poly1d"><code class="xref py py-obj docutils literal"><span class="pre">poly1d</span></code></a></span></dt>
<dd><span class="yiyi-st" id="yiyi-28">一维多项式类。</span></dd>
</dl>
<p><span class="yiyi-st" id="yiyi-29"><a class="reference internal" href="numpy.poly.html#numpy.poly" title="numpy.poly"><code class="xref py py-obj docutils literal"><span class="pre">poly</span></code></a>, <a class="reference internal" href="numpy.polyadd.html#numpy.polyadd" title="numpy.polyadd"><code class="xref py py-obj docutils literal"><span class="pre">polyadd</span></code></a>, <a class="reference internal" href="numpy.polyder.html#numpy.polyder" title="numpy.polyder"><code class="xref py py-obj docutils literal"><span class="pre">polyder</span></code></a>, <a class="reference internal" href="numpy.polydiv.html#numpy.polydiv" title="numpy.polydiv"><code class="xref py py-obj docutils literal"><span class="pre">polydiv</span></code></a>, <a class="reference internal" href="numpy.polyfit.html#numpy.polyfit" title="numpy.polyfit"><code class="xref py py-obj docutils literal"><span class="pre">polyfit</span></code></a>, <a class="reference internal" href="numpy.polyint.html#numpy.polyint" title="numpy.polyint"><code class="xref py py-obj docutils literal"><span class="pre">polyint</span></code></a>, <a class="reference internal" href="numpy.polysub.html#numpy.polysub" title="numpy.polysub"><code class="xref py py-obj docutils literal"><span class="pre">polysub</span></code></a>, <a class="reference internal" href="numpy.polyval.html#numpy.polyval" title="numpy.polyval"><code class="xref py py-obj docutils literal"><span class="pre">polyval</span></code></a></span></p>
<dl class="last docutils">
<dt><span class="yiyi-st" id="yiyi-30"><a class="reference internal" href="numpy.convolve.html#numpy.convolve" title="numpy.convolve"><code class="xref py py-obj docutils literal"><span class="pre">convolve</span></code></a></span></dt>
<dd><span class="yiyi-st" id="yiyi-31">数组卷积。</span><span class="yiyi-st" id="yiyi-32">与polymul相同的输出，但具有重叠模式的参数。</span></dd>
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<p class="rubric"><span class="yiyi-st" id="yiyi-33">例子</span></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">polymul</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">],</span> <span class="p">[</span><span class="mi">9</span><span class="p">,</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">1</span><span class="p">])</span>
<span class="go">array([ 9, 23, 38, 17,  3])</span>
</pre></div>
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<p><span class="yiyi-st" id="yiyi-34">使用poly1d对象：</span></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">p1</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">poly1d</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">p2</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">poly1d</span><span class="p">([</span><span class="mi">9</span><span class="p">,</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">1</span><span class="p">])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">p1</span><span class="p">)</span>
<span class="go">   2</span>
<span class="go">1 x + 2 x + 3</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">p2</span><span class="p">)</span>
<span class="go">   2</span>
<span class="go">9 x + 5 x + 1</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">polymul</span><span class="p">(</span><span class="n">p1</span><span class="p">,</span> <span class="n">p2</span><span class="p">))</span>
<span class="go">   4      3      2</span>
<span class="go">9 x + 23 x + 38 x + 17 x + 3</span>
</pre></div>
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